Identification of historical lead sources apportionments in estuary sediments from atmospheric aerosols/ NSW/Australia

Abstract of a poster that presented at the IAC2014 conference

Spatial and temporal distribution and pollution assessment of trace metals in marine sediments in Oyster Bay, NSW, Australia

The disposal of untreated urban and industrial wastewater has a deleterious effect on both the water and sediment quality of Oyster Bay located in south Sydney, Australia. The present investigation was undertaken to evaluate the potential pollution of marine sediments in Oyster Bay. The results of metals were compared with adverse biological effect values effect range low (ERL) and effect range median (ERM). Spatial distribution of trace metals was estimated by applying geographic information system. The results indicated that the sediments were polluted with Cu, Zn, As and Pb, which exceeded ERL levels. However, these metals were still below ERM values, and other metals Cr and Ni were below ERL. Moreover, the highest concentrations of metals were around discharge points and in the inner bay. Further, trace metals could be attributed to human activities within the bay as they declined in concentrations with increasing sediment depth

Source identification and assessment of sediment contamination of trace metals in Kogarah Bay, NSW, Australia

The distribution of trace metals (spatial and temporal) and sedimentary fractions were investigated to identify the concentrations and sources of trace metals within Kogarah Bay, NSW, Australia. A total of 59 surface sediments and six subsurface samples from core of the sediment were collected. The contamination factor and pollution load index indices used to evaluate environmental effects of trace metals. The study area was found to be uncontaminated with Cr and Ni, moderately contaminated with As and considerably contaminated with Cu, Zn and Pb. The concentrations of Cr and Ni were below both effect range low and effect range median, while As, Cu, Zn and Pb were slightly above effect range low. The highest concentrations of these trace metals such as Cu, Zn and Pb were found in the north, northwest and southeast of the bay, close to discharge points, stormwater outlets and around boatyards and watercrafts. The spatial distributions of metals were strongly related to muddy particles and organic matter. The temporal sediments of metals declined with increased sediment depth, which reflects accumulation of trace metals since European settlement in this area. Furthermore, the source of the trace metals was found to be stormwater outlets, gasoline fumes, boatyards and other human activities

Environmental assessment of benthic foraminiferal and pollution in Gunnamatta Bay, NSW, Australia

We investigated the distribution of trace metals (spatial and temporal) and sedimentary particles in order to identify the relationship between benthic foraminifera and trace metals pollution within Gunnamatta Bay, Port Hacking Estuary, NSW, Australia. Risk assessments of surface sediments were evaluated by using hierarchical cluster analysis (HCA). A total of 59 surface sediment samples and seven subsurface sediment samples were collected, in order to determine the levels of trace metals in spatial and temporal of the bay. Further, six surface sediment samples were examined for existing foraminiferal assemblages in muddy samples, which had high and low concentration of trace metals and sandy samples. The trace metals distribution showed that the trace metals such as chromium, nickel, copper, zinc, arsenic, lead, rubidium and bromine had similar distribution in surface sediments. The results of trace metal concentrations were compared with the deleterious biological effect values in marine sediments. The mean of most trace metals for the Bay were below the Effect Range Low except copper and Effect Range Median. The highest concentrations of these metals were found to be in the north east of the bay sample GU55, which is close to the proximity of discharge points, and craft boats (moored) with concentrations (107, 14, 398, 413, 8, 203, 27 and 182ppm) respectively. Also, this trace metal pollution is concentrated in the inner part of the bay, which is deep, and has organic matter and clay minerals. The benthic foraminferal assemblages has low species diversity in muddy samples GU25 and GU55 compared to the fine sandy particles in samples GU12 and GU24. Furthermore, the muddy particles that have had high level of trace metals were dominated by species tolerant- pollution such as Ammonia beccarii, Brizalina spathulata and Elphidium excavatum. These have had more opportunity to flourish. In addition, the values of trace metals dramatically decline with increasing depth. This reflects that the potential source of trace metal pollution is from human activity (eg. gasoline fumes and boats), since early European settlement in this area

Lead isotope fingerprinting used as a tracer of lead pollution in marine sediments from Botany Bay and Port Hacking estuaries, southern Sydney, Australia

Anthropogenic lead has been released into environmental ecosystems via human activities; essentially from mining, smelting of lead, leaded gasoline and industrial activities. In order to explore the source apportionment and historic record of lead pollution in the marine sediments, concentration of lead was determined from the Botany Bay and Port Hacking estuaries, south of Sydney, Australia. Areas with the highest concentrations of lead in the sediment samples were analysed by inductively coupled plasma-mass spectrometry (ICP-MS) for lead isotopes to effectively identify the metal contamination source. In addition, other sediment samples were collected from cores at 40 cm depth to represent the natural background composition. The study found that the total lead in the tested marine sediments varied from 75.6 mg/kg to 582.2 mg/kg. The 206Pb/204Pb showed a decline towards the current surface sediment. Assuming that the natural background source of lead remains the same in terms of both isotopic signature and accumulation rate, the decline in 206Pb/204Pb indicated a rise in the contribution of old lead to the sediment, mainly from gasoline fumes (car and boat exhausts) and paint. This is because the samples came from close to water discharge points which have concentrated the catchment lead via stormwater runoff

Spatial distribution of sediment particles and trace element pollution within Gunnamatta Bay, Port Hacking, NSW, Australia

A combination of geochemical analysis and hydrodynamic measuring has been established in order to provide an explanation for the spatial distribution of both sediment particles and trace element pollution Gunnamatta Bay, NSW, Australia. Fifty nine samples of surface sediment were collected to determine the spatial concentrations of trace elements in the bay. Moreover, current track pathways and velocities have been measured in the bay. The distribution of trace elements such as chromium, nickel, copper, zinc, arsenic and lead had similar patterns in surface sediments. Trace element pollution is concentrated along the current trajectory in the inner part of the bay, which has deeper sites and higher percentages of mud particles. The highest concentrations of these metals were found to be in sample GU55 from the northeast of the bay, which is close to a surface discharge point and moored boats

Modelling the future eco-geomorphological change scenarios of coastal ecosystems in southeastern Australia for sustainability assessment using GIS

Conference presentation

Basic life sciences

We investigated the distribution of heavy metals Ni, Cu, Zn, As, Cd and Pb in marine sediments in order to evaluate the pollution status in Yowie Bay, in the Port Hacking Estuary, NSW, Australia. Twenty one surface sediments were collected in this study and hydrodynamic parameters (current track and velocity) were also measured in order to explain the distribution of the heavy metals in the bay. Effect Range Low and Effect Range Median statistics were used to assess the environmental effect in order to offer measures to protect the ecosystem from pollution by the accumulation of heavy metals in the bay. The results showed that the heavy metals Ni, Cu, Zn, As, Cd and Pb had similar distribution patterns in surface sediments. The surface sediments were considerably contaminated by copper, cadmium and lead. The highest concentrations of the metals were found to be in the northeast of the bay, which is in close proximity to discharge points and moored watercraft, with the highest reading (sample YO8) having concentrations of 20, 107.4, 304.2, 15, 12.3 and 176.5 ppm, respectively. The heavy metal pollution was concentrated in the inner bay, which has greater depth and contains organic matter and muddy particles (illite, kaolinite and chlorite). The sources of pollution by heavy metals were found to be discharge points and human activities (gasoline fumes, watercraft and boatyards) and this pollution began with European settlement which now surrounds the bay

Removal of volatile organic compounds (VOCs) from groundwater by reverse osmosis and nanofiltration

A comprehensive study was conducted to examine the removal of volatile organic compounds (VOCs) which exist in groundwater at Southlands-Botany Bay (Sydney region). The ability of nanofiltration (NF) and reverse osmosis (RO) as advanced treatments was investigated using two commercially available NF or RO membranes. Laboratory-scale tests were used with cross-flow; tests were conducted with 16 ubiquitous compounds that represented the significant volatile organic compounds found in the contaminated groundwater. The results reported in this study indicate that the removal efficiency of reverse osmosis (RO) was better than NF in rejecting the VOCs detected in groundwater. This study revealed that the performance of NF and RO membranes in rejecting hydrophilic volatile organic compounds was higher than that for hydrophobic compounds and the highest rejection achieved by NF and RO membranes amounted 98.4% and 100%, respectively. Hydrophilic compounds can be effectively rejected by NF/RO membranes using the size exclusion mechanism (steric hindrance), whereas hydrophobic compounds can be adsorbed into NF/RO membranes and then diffuse through the dense polymeric matrix, resulting in the lower removal for these compounds compared to hydrophilic compounds